Solid adjuvant defoamer

ABSTRACT

A defoaming adjuvant comprises a solid particulate carrier and a polyalkylene glycol adsorbed on to the solid particulate carrier, where the polyalkylene glycol is a reaction product of an alkyl alcohol initiator with 1, 2-butylene oxide and, optionally, propylene oxide.

This application is a National Stage Application under 35 U.S.C. § 371of International Application Number PCT/CN2014/092769, filed Dec. 2,2014 and published as WO 2016/086349 on Jun. 9, 2016, the entirecontents of which are incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a defoamer adjuvant that has apolyalkylene glycol containing butylene oxide adsorbed onto a solidcarrier particle.

Introduction

Concentrates are a convenient and economical way to sell activecomponents for formulations such as agrochemicals. Concentrates can beshipped with a minimal amount of carrier fluid, such as water, and thendiluted in a carrier just prior to use by a consumer. That allows themanufacturer to avoid shipping water. However, consumers end up havingto mix up their own formulations by mixing concentrate and carrier toachieve a usable formulation. That process can often result in foamformation during the mixing process, which can undesirably cause delaysin preparing formulation and even loss of active if the foam froths outof the intended container. As a result, it is common for manufacturersto include defoamers in concentrate formulations to inhibit foamformation during dilution with a carrier.

Common defoamers for use in concentrates include organosilicone agents,perfluoroalkyl defoaming agents, and acetylenic diols. Organosiliconeagents tend to be expensive and can decompose under conditions used toprepare solid formulations, thereby losing efficacy as a defoamer.Moreover, organosilicone agents tend to create cloudy solutions, whichmake them undesirable for clear formulations. Perfluoroalkyl defoamingagents and acetylenic diols are effective defoamers in liquidformulations, but are less effective as a solid adjuvant and can bind upso tightly as to lose their defoaming efficacy. Propylene oxide (PO) orPO and ethylene oxide (EO) copolymers have also had some reportedsuccess as defoamers.

It is desirable to identify a defoamer that is less costly thanorganosilicone defoamers, that is particularly effective as a solidadjuvant unlike perfluoroalkyl defoaming agents and acetylenic diols andthat is more effective as a defoamer than PO and EO/PO copolymers.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a defoamer that is less costly thanorganosilicone defoamers, that is particularly effective as a solidadjuvant unlike perfluoroalkyl defoaming agents and acetylenic diols andthat is more effective as a defoamer than PO and EO/PO copolymers.

The present invention is a result of unexpectedly discovering that1,2-butylene oxide (BO) containing polyalkylene glycol polymers becomeespecially effective defoamers when adsorbed onto a solid substrate inthe form of a solid adjuvant, even more effective than when they areintroduced into a formulation in the liquid phase.

In a first aspect, the present invention is a defoaming adjuvantcomprising: (a) a solid particulate carrier; and (b) a polyalkyleneglycol adsorbed onto the solid particulate carrier, where thepolyalkylene glycol is a reaction product of an alkyl alcohol initiatorwith 1,2-butylene oxide and, optionally, propylene oxide.

In a second aspect, the present invention is a method for using thedefoaming adjuvant of the first aspect, the method comprising the stepof formulating the defoaming adjuvant with an agrochemical to form anagrochemical formulation.

The present invention is useful as a defoamer adjuvant in compositionssuch as agrochemical concentrates.

DETAILED DESCRIPTION OF THE INVENTION

“And/or” means “and, or alternatively”. All ranges include endpointsunless otherwise stated.

Test methods refer to the most recent test method as of the prioritydate of this document unless a date is indicated with the test methodnumber as a hyphenated two digit number. References to test methodscontain both a reference to the testing society and the test methodnumber. Test method organizations are referenced by one of the followingabbreviations: ASTM refers to ASTM International (formerly known asAmerican Society for Testing and Materials); EN refers to European Norm;DIN refers to Deutsches Institut für Normung; and ISO refers toInternational Organization for Standards. GB/T refers to Guobiao tuijianChinese national standard test methods issued by the Chinese NationalCommittee of the International Organization for Standardization andInternational Electrotechnical Commission.

EO, PO and BO refer respectively to the copolymerized component ofethylene oxide, propylene oxide and 1,2-butylene oxide in a polyalkyleneglycol polymer.

References to “CX” where “X” is a number refers to X number of carbonsin a molecular component. For example, C12 means 12-carbons.

The solid particulate carrier of the present invention includes thosecommonly useful in agrochemical formulations. Suitable particulatecarriers include any one or combination of more than one materialselected from a group consisting of solid silica white, starch,diatomaceous earth, montmorillonite, calcium carbonate and bentonite.Desirably, the particulate carrier is solid silica selected from a groupconsisting of fumed, precipitated silica and silica made by a gelformation technique.

Desirably, the solid particulate carrier has an average particle size of500 micrometers or smaller, preferably 400 micrometers or smaller, yetmore preferably 300 micrometers or smaller, even more preferably 200micrometers or smaller, still more preferably 100 micrometers or smallerand can be 10 micrometers or smaller, one micrometer or smaller and even100 nanometers or smaller and at the same time the average particle sizeis desirably one nanometer or larger and typically 10 nanometers orlarger and can be 100 nm or larger, one micrometer or larger, 10micrometers or larger, 100 micrometers or larger and even 200micrometers or larger. Determine average particle size by, for example,sieve analysis.

The polyalkylene glycol (PAG) of the present invention is adsorbed ontothe solid particulate carrier. Desirably, PAG is present at an averageconcentration of one weight-percent (wt %) or more, preferably five wt %or more, more preferably 10 wt % or more, yet more preferably 15 wt % ormore, even more preferably 20 wt % or more and can be present at aconcentration of 25 wt % or more, 30 wt % or more, 35 wt % or more, 40wt % or more, 45 wt % or more, 50 wt % or more, 55 wt % or more, 60 wt %or more and even 65 wt % or more. At the same time, PAG is typicallypresent at a concentration of 80 wt % or less and is generally 75 wt %or less and can be 70 wt % or less, 65 wt % or less, 60 wt % or less, 55wt % or less and even 50 wt % or less. It is most desirably for theconcentration of PAG to be 50 wt % or more. Determine wt % PAG relativeto combined weight of PAG and solid particulate carrier weight.

PAG can be adsorbed onto the particulate carrier by, for example,blending with the particulate material or spraying onto the particulatecarrier.

The PAG is a reaction product of an alkyl alcohol initiator with1,2-butylene oxide and, optionally, propylene oxide. The alcoholinitiator can have one, two or three hydroxyl groups on it. That is, thealcohol initiator can be a monol, diol (for example, propylene glycol)or triol (for example, glycerol). The PAG can be capped or, preferably,is terminated with a hydroxyl end cap. Hence, the PAG can have thegeneral formula:R¹[O-(PO)_(a)-(BO)_(b)-R²]_(c)where R¹ is the alkyl backbone remnant from the alkyl alcohol initiator,PO is a propylene oxide remnant after copolymerization, BO is a1,2-butylene oxide remnant after polymerization, R² is either a hydrogenor another capping group such as an alkyl, —C(O)R or benzyl, and a and bdesignate the number PO and BO units in the PAG copolymer on average.The value for a can be zero while the value for b is greater than zero.The value for c is selected from one, two or three and corresponds tothe number of hydroxyl groups on the alcohol initiator. The “end cap”for the PAG is the R² group combined with the oxygen of the alkoxy groupto which it attaches. For example, when R² is a hydrogen the PAG isdeemed to have a hydroxyl (—OH) end cap. When R² is an alkyl, the PAGhas an ether (—OR²) end cap and when R² is C(O)R the PAG has an ester(—OC(O)R) end cap.

The alkyl alcohol initiator corresponds to the structure R¹[OH]_(c)where R¹ is the same in the alcohol structure and PAG structure aboveand c is the same value as c in the PAG structure above. The alkylalcohol initiator, and therefore R¹, can contain one carbon or more andgenerally contains 30 carbons or less. Some desirable alkyl alcoholinitiators (and R¹ groups) contains 6 or more, 8 or more carbons, 10 ormore carbons, 12 or more carbons, 14 or more carbons 16 or more carbons,18 or more carbons even 20 or more carbons on average over all PAGmolecules. The PAG can comprise a combination of PAG molecules, eachhaving R¹ carbon lengths within the scope of these suitable values. R¹can be linear or branched where “linear” means that each carbon has onlyone or two carbons attached to it and “branched” means at least onecarbon has at least three carbons attached to it. Examples of suitablealkyl alcohol initiators include those selected from dodecanol and1,2-propylene glycol.

When both PO and BO are present, they may be present in blocks in anyorder (that is, either PO or BO can be attached to the R¹O group) orrandomly copolymerized in the PAG structure. The PAG can be free of POand, hence, comprise only 1,2-butylene oxide. For avoidance of doubt,the PAG of the present invention is free of multiple copolymerizedethylene oxide units (that is, —CH₂CH₂O— units). When both PO and BO arepresent, it is desirable that PO be present at an average concentrationof 20 wt % or more, preferably 30 wt % or more, more preferably 40 wt %or more, yet more preferably 50 wt % or more and PO can be present at aconcentration of 60 wt % or more, 70 wt % or more and even 80 wt % ormore while at the same time PO is desirably present at a concentrationof 80 wt % or less, preferably 70 wt % or less, more preferably 60 wt %or less, yet more preferably 50 wt % or less and can be present at aconcentration of 40 wt % or less, 30 wt % or less and even 20 wt % orless based on combined weight of PO and BO in the PAG.

The PAGs of the present invention desirably have an average molecularweight of 300 grams per mole (g/mol) or more, preferably 400 g/mol ormore, and can have a molecular weight of 500 g/mol or more, 600 g/moleor more 700 g/mol or more, 800 g/mol or more, 900 g/mole or more andeven 1000 g/mole or more while at the same time typically have amolecular weight of 3000 g/mol or less, preferably 2500 g/mole or less,more preferably 2000 g/mol or less and can have a molecular weight of1500 g/mol or less, 1400 g/mol or less, 1300 g/mole or less, 1200 g/molor less, 1100 g/mol or less, 1000 g/mol or less, 900 g/mol or less andeven 800 g/mol or less. Molecular weights herein refer to weight averagemolecular weight unless otherwise stated. Determine PAG molecularweights from their hydroxyl number. Determine hydroxyl number andmolecular weight according to ASTM D4274.

A surprising discovery with the present invention is the fact that thereappears to be a synergistic defoaming effect between the solidparticulate carrier and PAG component that accentuates the defoamingproperties of the combined adjuvant over the defoaming property ofeither component individually. As demonstrated in the Examples sectionbelow, the adjuvant of the present invention comprising the PAG adsorbedonto a solid particulate carrier shows greater defoaming efficacy thaneither PAG alone or the solid particular carrier alone. This isunexpected and not universally true for all PAG materials. Therefore,there appears to be something special and unique about the BO-containingPAGs that facilitates this synergistic defoaming effect.

The defoaming adjuvant of the present invention can be free ofconventional defoamers such as organosilocone materials, perfluoroalkylmaterials and acetylenic diols. Also, the present invention can be freeof surfactants enclosing the PAG on the surface of the solid particulatecarrier. Some teachings specify that surfactants must enclose thedefoamer on the surface of a particulate carrier, but that is notnecessary in the present invention.

The defoaming adjuvant of the present invention is useful for use in themethod of the present invention, which comprises formulating thedefoaming adjuvant with an agrochemical such as a pesticide to form anagrochemical formulation. The formulation can be liquid or solid. Thedefoaming adjuvant and/or the formulation can be diluted with a solid orliquid carrier such as a solid filler and/or water to form aformulation. The benefit of the defoaming adjuvant is that when it isadded to a liquid carrier the defoaming adjuvant serves to minimize foamformation.

Examples

Use the water dispersible granule formulation of tebuconazole listed inTable 1 to screen both the defoaming efficacy and dispersing performancefor water dispersible formulations of these examples. Concentrations arein weight-percent relative to total formulation weight.

Prepare a water dispersible granule composition from the formulation inTable 1. First mix the components together and mechanically crush themixture to reduce particle size. Add dropwise enough water to plasticizethe mixture slightly (15-20 wt % based on total mixture weight). Add theplasticized composition to an extrusion granulating machine to formextruded granulated products and then dry at 50-60 degrees Celsius (°C.). The final product is obtained by sieving with 10, 20 and 40 meshsieves.

TABLE 1 Concen- tration (wt %) Component Component Description 80Tebuconazole Triazole fungicide. (RS)-1-(4-Chlorophenyl)-4,4-dimethyl-3-(1H, 1,2,4-triazol-1-ylmethyl)pentane-3-ol5 DURAMAX ™ Acrylate polymer, polycarboxylate D-518 dispersing agent.DURAMAX is a dispersant trademark of Rohm and Haas Company. 4 OROTAN ™Naphthalene condensate. OROTAN SN dispersant is a trademark of Rohm andHaas Company. 2 AOS/92 Alpha olefin sulfonate from Sinolight. CAS number68439-57-6. 9 Calcium Filler. Carbonate

Antifoaming Efficacy Testing

To screen defoaming (actually, antifoaming) efficacy, the PersistentFoam Volume test method of GB/T 28137-2011, summarized as follows:

-   -   (1) Weigh approximately 180 grams (g) of standard water into a        250 milliliter (mL) graduated cylinder with glass stopper. The        distance between the zero mark and the 250 mL mark of the        cylinder is 20-21.5 centimeters (cm), and the distance between        the 250 mL mark and the bottom of the stopper is 4-6 cm.    -   (2) Add 1.0 g of water dispersible granules into the water.    -   (3) Add standard water into the cylinder until the distance        between the surface and the bottom of the stopper is 9 cm.    -   (4) Stopper the cylinder and invert 30 times within one minute.    -   (5) Place the cylinder upright and immediately record the foam        height (initial ht) and record the foam height again after one        minute (1 min ht).    -   * standard water is 1000 mL of deionized water with 0.304 g        anhydrous calcium chloride and 0.139 g magnesium chloride        hexahydrate dissolved therein.

Dispersing Performance

Characterize the dispersibility of a water dispersible granule by addinga one gram sample of the water dispersible granule into 250 mL of waterin a 250 mL graduated cylinder. Invert the graduated cylinder at a rateof two inversions per second. Record the number of inversions needed tocompletely dissolve the granules. Complete dissolution should occurwithin ten inversions.

Comparative Example (Comp Ex) A—Blank

Characterize the Antifoaming Efficacy and Dispersing Performance of thetebuconazole water dispersible granule formulation to establish abaseline performance without the presence of defoamer. In theantifoaming Efficacy Testing the initial ht is 63+/−6 mL and the 1 minht is also 63+/−6 mL. In the Dispersing Performance test, completedissolution occurs within 10 inversions.

Comp Exs B-F—Separate Defoamer Addition

Screen five different PAG defoamers, described in Table 2, for theirefficacy in preventing foaming and breaking up foam that does form induring the Antifoaming Efficacy screening of the base tebuconazoleformulation. Conduct the screening by completing steps (1)-(3) of theAntifoaming Efficacy test as in Comp Ex A but prior to step (4) add 0.01g of one of the PAG defoamers from Table 2. Results from the AntifoamingEfficacy test are included in Table 2. Each formulation dispersedcompletely within 10 inversions in the Dispersing Performanceevaluation.

The data in Table 2 reveals that each of the defoamers acts as anantifoaming agent in the formulation by reducing foam height from 63 mLas observed with the Blank to 40 mL or less.

TABLE 2 Initial 1 Min Comp Ex Defoamer Description Ht (mL) Ht (mL) BDOWFAX ™ Polypropylene glycol, molecular 35 35 DF-106 weight ofapproximately 3800 g/mol. defoamer DOWFAX is a trademark of The DowChemical Company. C DOWFAX ™ C12-C15 alcohol ethylene oxide/ 30 30 DF142propylene oxide copolymer DOWFAX is a trademark of The Dow ChemicalCompany. D POLYGLYCOL Linear polypropylene glycol having a 40 40 P-4000Emolecular weight of approximately 4000 g/mol. Available from The DowChemical Company. E UCON ™ Dodecanol initiated random 35 35 OSP-18copolymer of propylene oxide and butylene oxide (50/50 by weight) with atypical kinematic viscosity of 4 centiStokes at 100° C., averagemolecular weight of 500 g/mol and a viscosity index of 123. UCON is atrademark of Union Carbide Corporation. F UCON ™ Dodecanol initiatedrandom 35 35 OSP-32 copolymer of propylene oxide and butylene oxide(50/50 by weight) with a typical kinematic viscosity of 6.5 centiStokesat 100° C., average molecular weight of 760 g/mol and a viscosity indexof 164. UCON is a trademark of Union Carbide Corporation.

Comp Exs G-K—Neat Defoamer in Water Dispersible Granule

Prepare water dispersible granules using a modified form of theformulation in Table 1, modified by using 7 wt % calcium carbonate and 2wt % of one of the defoamers listed in Table 2. The objective is toprepare water dispersible granules that have neat defoamer incorporatedtherein. Screen the resulting granules for Antifoaming Efficacy andDispersing Performance.

Results for the different formulations are in Table 3. None of thegranules completely disperse din the Dispersing Performance test.

TABLE 3 Initial 1 Min Comp Ex Defoamer Ht (mL) Ht (mL) G DOWFAX ™ DF-106defoamer 60 60 H DOWFAX ™ DF142 55 55 I POLYGLYCOL P-4000E 60 60 JUCON ™ OSP-18 55 55 K UCON ™ OSP-32 60 60

The data in Table 3 reveals that each of the defoamers acts as anantifoaming agent to a much smaller extent when formulated as a needadditive in the water dispersible granule, reducing foam height from 63mL as observed with the Blank to 55-60 mL. The defoamers are all lesseffective formulated neat into the water dispersible granule than whenadded to a solution separate from the water dispersible granule.

Comp Exs L-R and Examples (Exs) 1-4—Solid Defoaming Adjuvant

Defoamers are once again formulated into the water dispersible granulesbut this time the defoamers are first formulated into a solid defoamingadjuvant by adsorbing the defoamer onto silica white particles. Thesilica white particles have an average particle size in a range of100-200 micrometers, commercially available under the name NEWSIL™ C80(NEWSIL is a trademark of Mc Ghan Nusil Corporation).

Prepare the solid defoaming adjuvant by placing 20 g of a defoamer intoa 100 mL transparent bottle and begin slowly agitating. Slowly addsilica white to the defoamer while agitating and avoiding clumping. Usea glass rod if necessary to break up any clumps that form. Add silicawhite powder to achieve a total composition that is approximately 35-40wt % silica white and balance being defoamer. Table 4 discloses thecomposition of the solid defoaming adjuvants for use in this screeningand the concentration of defoamer in the adjuvant as a wt % of totaladjuvant weight. Notably, there are several additional defoamers used inthis screening:

-   -   POLYGLYCOL P-1000E. Linear polypropylene glycol having a        molecular weight of approximately 1000 g/mol. Available from The        Dow Chemical Company.    -   POLYGLYCOL P-2000E. Linear polypropylene glycol having a        molecular weight of approximately 2000 g/mol. Available from The        Dow Chemical Company.    -   UCON™ OSP-320 synthetic polyalkylene glycol. A 1,2-propylene        glycol initiated BO homopolymer, hydroxyl capped, with a typical        kinematic viscosity at 40° C. of 320 centiStokes and average        number average molecular weight of 2800 g/mol.    -   TANAFOAM SLX. Fatty acid, tallow, sodium salts available from        Tanatex Chemicals.

TABLE 4 Concentration of Defoamer on Defoamer Solid Defoamer Adjuvant(wt %) DOWFAX ™ DF106 65.1 DOWFAX ™ DF142 64.6 POLYGLYCOL P1000E 64.1POLYGLYCOL P2000E 64.8 POLYGLYCOL P4000E 64.6 UCON ™ OSP-18 63.3 UCON ™OSP-32 65.7 UCON ™ OSP-320 58.8

Screen the solid defoamer adjuvants in like manner as in Comp Exs G-K,except formulate the solid defoaming adjuvant instead of neat defoamingagent into the water dispersible granule. For consistency, formulate soas to obtain 1.5-1.7 wt % active defoamer in the water dispersiblegranule. Also screen an additional Comp Ex that screens just the silicawhite powder without a defoamer to reveal the effect of the silica whiteparticles. Results are in Table 5. All water dispersible granulescompletely dissolved within 10 inversions in the Dispersing Performancescreening. Defoamer concentration is in wt % relative to total waterdispersible granule weight.

TABLE 5 Defoamer Initial 1 Min Example Defoamer Concentration Ht Ht CompEx L (none) 0 63 63 (1.58 wt % silica) Comp Ex M DOWFAX DF106 1.54 40 40Comp Ex N DOWFAX DF142 1.55 50 45 Comp Ex O POLYGLYCOL 1.56 65 65 P1000EComp Ex P POLYGLYCOL 1.54 50 45 P2000E Comp Ex Q POLYGLYCOL 1.55 50 45P4000E Ex 1 UCON ™ OSP-18 1.58 25 25 Ex 2 UCON ™ OSP-32 1.52 30 30 Ex 3UCON ™ OSP-320 1.70 40 40 Comp Ex R Tanafoam SLX 1.50 45 45

The data in Table 5 reveals a surprisingly synergistic affect at foamreduction when BO-containing PAG is adsorbed onto a solid particularcarrier and then formulated into a water dispersible granule that isunique to the BO-containing PAGs. Comp Ex L reveals that silica powder(the solid particulate carrier) alone has no effect on the foamformation. Comp Exs M-Q also reveal that adsorbing PAGs without BO ontosilica powder results in little increase in anti-foaming effect relativeto the PAGs formulated into a water dispersible granule and decreasedanti-foaming affect relative to PAG added separately from waterdispersible granules.

In contrast, Exs 1-3 illustrate that the BO-containing PAGs show greateranti-foaming affect when adsorbed onto the particulate carrier andformulate into the water dispersible granule than when added separatefrom the water dispersible granule or formulated in any of the otherways into the water dispersible granule. This surprising unique behaviorprovides a beneficial increase in defoaming properties that is specialfor the BO-containing PAGs.

Comp Ex R provides a comparison to a standard defoaming additive forsuch formulations. The data reveals that the BO-containing PAGs alsoprovide greater anti-foaming effect than the standard defoamer when thePAG is adsorbed onto a particulate carrier and formulated into the waterdispersible granule.

What is claimed is:
 1. A defoaming adjuvant comprising: a) a solidparticulate carrier; and b) a polyalkylene glycol adsorbed onto thesolid particulate carrier, where the polyalkylene glycol is a reactionproduct of a C10 to C14 alkyl alcohol initiator with 1,2-butylene oxideand propylene oxide.
 2. The defoaming adjuvant of claim 1, furthercharacterized by the polyalkylene glycol having a hydroxyl end cap. 3.The defoaming adjuvant of claim 1, further characterized by thepolyalkylene glycol having an average molecular weight in a range of400-3000 grams per mole.
 4. The defoaming adjuvant of claim 1, furthercharacterized by the solid particulate carrier being silica particles.5. The defoaming adjuvant of claim 1, further characterized by beingfree of organosilocone materials, perfluoroalkyl materials andacetylenic diols.
 6. The defoaming adjuvant of claim 1, wherein thedefoaming adjuvant is free of surfactants enclosing the polyalkyleneglycol on the surface of the solid particulate earner.
 7. A method forusing the defoaming adjuvant of claim 1, the method comprising the stepof formulating the defoaming adjuvant with an agrochemical to form anagrochemical formulation.
 8. The method of claim 7, furthercharacterized by the agrochemicals comprising a pesticide.
 9. The methodof claim 7, further comprising the step of diluting the agrochemicalformulation with water.